It sounds like you got a rogue app wrecking havoc. You could try uninstalling each app till it runs okay but Amazon will tell you to do a factory reset.
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I agree. LCD displays should not get "burn-in" causing ghosting. Any residual pixels must be a software problem. It *could* be a firmware or software bug, but unlikely. There is an old hacker tradition of creating malware that SIMULATES hardware problems, and this sounds like it could be the same thing.

Perhaps you have full memory from too many apps. Android runs on top of linux. Linux can kill processes when it runs out of memory, and perhaps the screen contains part of an image because something was killed while drawing to the screen.

You did not describe details of the onscreen stuff that you thought may be "burn-in" (ghosting). Perhaps a screenshot would show what you saw. Residual pixels that did not get redrawn are not burn-in.